help! losing coolant.

[flagship202]

Ive got a GM 4.3l vortec V6. Lately Ive been smelling coolant when exiting the vehicle after driving but noticed no leaks. Today however the coolant is running on the ground underneath the vehicle. It seems to be running off the bellhousing and trans. No crankcase contamination. Your thoughts and ideas would be greatly appreciated. TIA flagship202

[price111]

One possibility - There are two heater hoses on my '99 that go into the firewall for the heater core. Since these are located above the location you are describing, you might check these. If they are leaking, there should be coolant under them. Feel them when it cools off, of course. There are other possibilities but start with the simple stuff first.

BTW - These hoses are a dealer item only as I replaced these last year for general maintenance. I usually always replace all the rubber hoses every 4-5 years, while changing the coolant at the same time.

LOL

[Alexxn 00 Si]

Originally Posted by flagship202

Ive got a GM 4.3l vortec V6. Lately Ive been smelling coolant when exiting the vehicle after driving but noticed no leaks. Today however the coolant is running on the ground underneath the vehicle. It seems to be running off the bellhousing and trans. No crankcase contamination. Your thoughts and ideas would be greatly appreciated. TIA flagship202

Sounds like the exact thing that happened to me....it was the lower intake manifold gasket. It was leaking where the manifold bolts to the heads and running to the back of the engine and dripping down by the bellhousing.

[sandystream]

I have 1993, 4.3. if your losing fluid about as fast as you can put it in and it is coming out pretty fast, and it looks like the leak is between the rear of the engine and transmission, this happened to me also. Unfortunetely, I could not do the repair myself because the coolant was flowing out the rear freeze plugs, yeah can you believe they put plugs between the engine and trany, It cost me about $200 to have my mechanic separate the engine from the trany and replace the plugs. good Luck!

[Timba123]

Greetings,
I did not see what year vehicle you have. I had the same problem/location with my 91 S10 blazer. The problem turned out to be a quick connect fitting for one of the heater hoses. It is mounted on the top of the engine block behind the air intake. The original was made of cheap pot metal and it just rusted out. I would smell the coolant, but could never find the leak because the majority of the time it evaporated. I found the part at Pep Boys for about $15, but I had to have the old one drilled out and the hole retapped because the old one rusted so bad. Never had any problems since. Hope this helps.

Tim

[tom3]

If this is a late model Blazer, probably the intake gasket. New intake style has a thick rubber coated plastic gasket and the intake bolts are pulling straight down, and torqued to a very low tension. Poor setup at best, short trip driving is especially hard on this setup. Expensive to repair if out of warranty, if in warranty they will do about anything to avoid fixing it, adding stop leak to get it through the warranty if possible. Keep us posted with this.

[Macgyver007]

Had the same problem with my 97.
On Mine it turned out to be the intake dome gasket.
Could only see the trickle down the back of the block with a trouble light and a small Mirror.

HTH
Mack

[flagship202]

Thanks to all who answered. It turned out to be the intake gasket as some suggested.It took about 6 hr. and 25.00 in parts to replace.As a side note,be very careful when reinstalling wire harness plug into cpi unit. I bent a pin and spent the next two days trying to figure out why I had an engine miss. flagship202

[jkdon]

How difficult was it to replace the intake gasket? I'm having the same problem and hoping todo the job myself. How much torque do you give the intake bolts, and do you use any kind of sealent? RTV etc.

thanks JKDon

[flagship202]

Greetings jkdon,
Replacing the intake gaskets on my 97 4.3 was not really difficult but takes some patience.Make sure you note how the sensor wires are ran. No two connectors were the same so theres not much chance for a mix up.The A/C pumps needs to be loosened and slid over to access the manifold. Be extra careful that you mark the distributor housing and rotor position so that they are replaced exactly the same as they came out. directions for the gaskets were on the package that mine came in. These gaskets are made from some kind of silicone composition and reqire very little torque about 14 ft. lbs. A torque wrench is highly recommended. RTV sealer is used as the gasket on the front and back of the manifold. It took me 6 hrs to do the first one but I think I could the second in a lot less time. A repair manual would probably come in handy depending on your experience. Hope this helps.
flagship202

[tom3]

Flagship: Looking at this job in the very near future myself. Wondering about that AC comp. Did you loosen the whole bracket or just the compressor? See two bolts in the lower bracket behind the PS pump, have to remove the pulley on pump to get them out? Everything else looks pretty basic.

[flagship202]

Hello tom3, regarding the A/c compressor, I removed it from the mounting brkt and moved it aside. The mounting brkt will need to be loosened but not removed.If I remember right there are 2 or 3 bolts going in from the front and 1 behind the pulley. The pulley does not have to be removed. I took off the left front tire and removed the inner fender skirt which allowed easy access. There are 8 or 10 bolts holding the skirt but they are easy to remove and the skirt drops out with no problems. Let me know how everything works out, flagship202

[tom3]

Thanks for info, never thought about going through the inner fender, good idea. Talking to a local mechanic the other day, says his retirement is looking real good from all the money he's making off GM's coolant fiasco, leaks and turning to mud. My Blazer is still under warranty, but they won't fix it since they can't see it leaking out on the ground. What a mess. Anyway, thanks again.

[jkdon]

thanks Flagship. The thing runs great and haven't seen a drop yet. Your advice saved me some cash.

Jkdon

[Wildman98]

Had a Similar problem with my 98, turned out to be a freeze plug behing the starter had a hole in it. Good luck